Lawn mower blades suffer brutal wear and tear during a mowing season. They should be inspected before each mowing session for nicks, rust and damage. Always handle a 54-inch blade with caution when performing maintenance. These blades are sharp and are longer in length than most mower blades. This can make them difficult to hold. The blades should be replaced or sharpened annually, if it is not necessary during the mowing season.
Park the mower on a level surface. Engage the "Park" brake and remove the spark plug wire from the spark plug.
Remove the mower deck from the mower. Raise the deck engagement lever to its highest setting. Place wood blocks under the deck on each side to secure the deck when it is lowered. Unscrew the bolts on the sides of the engine pulley with a wrench. Remove the drive belt from the engine pulley. Detach the deck hanger links from the mower, and raise the deck engagement lever to the disengage position. Remove the wood blocks. Roll the deck from underneath the mower.
Turn the deck over so the 54-inch blades are exposed. Unscrew the nut at the center of the blade, turning counterclockwise. Wedge a block of wood against the blade to stabilize the blade during removal. Remove the blade, sliding it up the spindle.
Attach a new blade with the curved end of the blade pointing towards the mower deck. Secure the blade onto the spindle with the nut. Turn clockwise to tighten the nut onto the blade.
Turn the deck right side up. Roll it under the mower. Lower the deck engagement lever to its lowest setting. Attach the deck hanger links to the mower and attach the drive belt to the engine pulley. Screw the bolts into the deck on the sides of the engine pulley, and raise the deck engagement lever to its highest position.
Reattach the spark plug wire to the spark plug.